#define SENTINAL (((uint64_t)1) << 63)

if (ops[0] == SENTINAL && ops[1] == SENTINAL) {
  back_array[0] = 0;
  back_array[1] = 0;
  discard = true;
  return -1;  // don't generate anything
} else if (ops[0] <= ops[1] || ops[1] == SENTINAL) {
  back_array[0] = 0;
  back_array[1] = 1;
  return ops[0];
} else if (ops[1] < ops[0] || ops[0] == SENTINAL) {
  back_array[0] = 1;
  back_array[1] = 0;
  return ops[1];
} else {
  assert(0 && "not possible");
}

#undef SENTINAL
